Inexpensive Android tablets made gains against Apple's iPad during the third quarter. Worldwide, tablet shipments totaled 47.6 million units, representing 7% growth over the previous quarter and 36.7% growth compared to the year-ago period, reports IDC. The aggressive influx of Android tablets helped increase the size of the market.

Apple refreshed its tablet lineup in October 2012 and again in October this year. With no new tablets on store shelves throughout most of 2013, however, Apple saw shipments drop from 14.6 million during the second quarter to 14.1 million during the third quarter. Despite the dip in shipments, Apple is still the world's largest supplier of tablet computers. Apple holds 29.6% of the market, its lowest share since introducing the iPad in 2010.

If you're worried about Apple's direction in the market, don't be. The company's iPad Air hits store shelves November 1 and the iPad Mini with Retina Display follows later in the month. IDC is sure that Apple will have a bonanza holiday quarter, which should help it win back some of the market share it lost over the last few months.

At the same time, low-cost Android tablets flooded the market. Google's Nexus 7 tablet, which is made by Asus and costs just $229, hit store shelves during the third quarter, as did the Samsung Galaxy Tab 7 version 3.

Samsung ranked second in overall market share, with shipments of 9.7 million tablets. These include its Note 8, Note 10.1, Galaxy Tab 7 and Tab 10, and the Nexus 10, to name a few. Samsung's shipments gave it 20.4% of the worldwide tablet market.

The Nexus 7 likely helped Asus land in the third spot. It shipped 3.5 million tablets during the second quarter and secured 7.4% of the worldwide market for tablets. The Nexus 7 offers a lot of bang for the buck, thanks to an HD screen, stereo speakers and the stock version of Google's Android operating system.

Lenovo moved into fourth place, with shipments of 2.3 million and market share of 4.8%. It was followed by Acer, which shipped 1.2 million tablets and earned 2.5% of the market.

IDC points out that more than a third of the entire tablet market belongs to "others." Shipments of tablets from Amazon, Dell, HP, Microsoft and white box vendors total 16.8 million units and 35.3% of the market.

"White box tablet shipments continue to constitute a fairly large percentage of the Android devices shipped into the market," said Tom Mainelli, research director, tablets at IDC. "These low cost Android-based products make tablets available to a wider market of consumers, which is good. However, many use cheap parts and non-Google-approved versions of Android that can result in an unsatisfactory customer experience, limited usage and very little engagement with the ecosystem. Android's growth in tablets has been stunning to watch, but shipments alone won't guarantee long-term success. For that you need a sustainable hardware business model, a healthy ecosystem for developers and happy end users."

It's a shame that IDC's numbers don't provide more specifics on Microsoft's efforts. The company was forced to write down its inventory of unsold Surface RT tablets, but introduced the second-generation Surface and Surface Pro machines earlier this month. Sales of its new hardware wouldn't be reflected in IDC's third-quarter numbers. With two new tablets in the game and Windows 8.1, however, Microsoft may push up against some of the low-cost Android tablet makers and see market share gains during the holiday shopping season.